Television gaming apparatus

ABSTRACT

The present invention pertains to an apparatus .[.and method.]., in conjunction with standard monochrome and color television receivers, for the generation, display, manipulation, and use of symbols or geometric figures upon the screen of the television receivers for the purpose of .[.training simulation, for.]. playing games.[., and for engaging in other activities.]. by one or more participants. The invention comprises in one embodiment a control unit, .Iadd.an apparatus .Iaddend.connecting .[.means.]. .Iadd.the control unit to the television receiver .Iaddend.and in some applications a television screen overlay mask utilized in conjunction with a standard television receiver. The control unit includes the control .[.means.]. .Iadd.circuitry.Iaddend., switches and .Iadd.other .Iaddend.electronic circuitry for the generation, manipulation and control of video signals which are to be displayed on the television screen. The connecting .[.means.]. .Iadd.apparatus selectively .Iaddend.couples the video signals to the receiver antenna terminals thereby using existing electronic circuits within the receiver to process and display the signals .Iadd.generated by the control unit in a first state of the coupling apparatus and to receive broadcast television signals in a second state of the coupling apparatus.Iaddend.. An overlay mask which may be removably attached to the television screen may determine the nature of the game to be played or the training simulated. Control units .[.are.]. .Iadd.may be .Iaddend.provided for each of the participants. Alternatively, games.[., training simulations and other activities.]. may be carried out in conjunction with background and other pictorial information originated in the television receiver by commercial TV, closed-circuit TV or a CATV station.

This is a continuation of application Ser. No. 697,798 filed Jan. 15,1968 now abandoned.

BACKGROUND OF THE INVENTION

The invention relates to an apparatus .[.and method.]. by means of whichstandard television receivers can be utilized as active rather thanpassive instruments. this is accomplished by certain embodiments havingparticipants manipulate controls of a control unit connected to thetelevision receiver to cause a symbol, such as a rectangle, bar, "dot"or a pair of dots to be displayed upon the television screen by means ofwhich the participants can play a variety of games.[., participate insimulated training programs, as well as carry out other activities.]..By way of example, modified versions of the well-known game of checkersmay be played by two participants by placing an appropriate maskrepresenting the checker board upon the screen of the televisionreceiver. .[.For a simulated training program, "dots" displayed on theTV screen could represent ships which would be maneuvered by operatingmanipulating controls..].

Heretofore, color and monochrome television receivers have been used bythe home and the other viewers only as passive devices; i.e., thetelevision receiver is used only as a display means for programmingoriginating at a studio. The viewer is limited to selecting thepresentations available for viewing and is not a participant to theextent that he can control or influence the nature of, or add to thepresentation displayed on the receiver screen. A standard receiver isemployed with auxiliary equipment to provide an active form of homeentertainment. Since most homes are equipped with television receivers,the only expense required to provide added family enjoyment is theexpense of a control unit of one type or another.

It is, therefore the primary object of the present invention to providean apparatus and methods for displaying video signals upon the screen ofa television receiver, where some or all of the video signals are bothgenerated and controlled by the viewer.

It is another object of the present invention to provide an apparatusand method wherein a standard color or monochrome television receiver isutilized as an active instrument .[.for simulated training programsand.]. to play various types of games involving one or moreparticipants.

It is a further object of the present invention to provide a devicewhereby an individual may pit his alertness, skill, manual dexterity andvisual acuity on automatically controlled video displays.

It is still another object of the present invention to provide anapparatus which will also provide visual indication of the results ofthe games played .[.and the simulated training programs..].

It is yet a further object of the present invention to provide anapparatus which will generate "dots" or other geometric figures such assquares, rectangles, bars, stripes, etc. .[.Which.]. .Iadd.which.Iaddend.may be controlled by one or more participants for playingvarious types of games .[.and for training simulation.]. by the displayand utilization of the "dots."

It is yet another object of the present invention to provide anapparatus which may allow one or more participants to use a standardtelevision set while receiving background and other pertinent pictorialinformation from a cooperative commercial TV, closed-circuit TV, or CATVstation, thus combining or alternating studio and home-generatedinformation on the TV screen.

It is still another object of the present invention to allow the use ofa standard TV set for gaming .[.or other activities.]. without the needfor any kind of internal electrical connection to the TV set for theintroduction of video and/or chroma signals, connections being requiredto be made only to the externally accessible antenna terminals.

It is still another object of the present invention to provide forinterrogating a standard TV receiver through an optical photosensor in amanner allowing the identification of a suitably time-or frequency-codedmessage, not interpretable by the unaided eye, such message having beenoriginated in the TV viewers equipment by a cooperative commercial TV,closed-circuit TV or CATV station.

It is still a further object of the present invention to provideapparatus for decoding messages on a TV screen.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the present invention a televisiongaming apparatus is provided for generating video signals in accordancewith the standardized television format, which signals may be controlledby an individual operator by means of a joystick or other manuallyoperative means. The television gaming apparatus comprises a control boxhaving enclosed therein all the necessary electronic circuits to producevideo signals which are compatible with standard television receivers,both monochrome and color.

The control box has video signal control means mounted thereon for easyaccess and connecting means are provided for .Iadd.directly andselectively .Iaddend.coupling the video signals generated within thecontrol box to the television receiver .Iadd.in a first state of theconnecting means and the television receiver is capable of receivingbroadcast television signals in a second state of the connectingmeans.Iaddend.. There is also provided suitable overlay masks which areadapted to be removably secured upon the television screen. These maskspermit playing of games .[.and training simulation.]. which areadaptable to display upon a television screen.

By way of illustration, the television gaming apparatus can be used forelectronic target shooting by providing a gun having a photo-electriccell which is activated when a trigger is depressed. Thus, when the gunis aimed at a "dot" displayed on the television screen, which "dot"serves as the target, and the trigger is depressed, a hit will beindicated directly on the television screen by a visual display when thephotoelectric cell is in alignment with the "dot." The "dot" whichserves as the target may be either fixed or moveable and can be sweptacross the screen in a predetermined or random fashion, at either afixed or variable rate, either manually or automatically.

By way of further illustration, games may be played in which acooperative TV station (commercial, closed-circuit or CATV) providesbackground data such as scenery for a simulated turkey-shoot game, orsuch as checkerboard game backgrounds, time-left-to-play-clocks andinnumerable others designed to enhance the appeal of the activity. Acooperative TV station can also provide targets for a target shootinggame as well as messages to be decoded. For example, tests questionscould be displayed on the TV screen with a multiple set of answerswhereby the correct answer is coded in such a manner that a photocellcircuit would detect the coding signifying selection of the correctanswer.

From the above illustrations it will be apparent to those skilled in theart, that the present invention exhibits a great latitude ofversatility.

BRIEF DESCRIPTION OF THE DRAWINGS

The aforementioned and other objects, features and advantages of thepresent invention will become more apparent from the following detaileddescription thereof when considered in conjunction with the drawingswherein:

FIG. 1 is a pictorial view illustrating the principal components of oneembodiment of the invention;

FIG. 1A is a sketch illustrating the manner in which the components ofthe embodiment of FIG. 1 are connected;

FIG. 1B is a pictorial view illustrating an alternate embodiment for thecontrol unit of FIG. 1;

FIG. 1C is a sketch showing a "light-gun" containing a photocell andelectronic circuits.

FIGS. 1D and 1E are sketches illustrating the manner in which thecomponents of the embodiment of FIG. 1 may be connected when used with acooperative TV station.

FIG. 2 is a sketch illustrating a TV screen and overlay mask as employedin the embodiment of FIG. 1;

FIG. 3 is a block diagram of the control unit of FIG. 1;

FIG. 4 is a schematic illustrating the electronics for a target shootinggame;

FIGS. 5A-5G are schematics of the blocks of FIG. 3;

FIGS. 6A-6F are waveforms (not drawn to scale) illustrating operation ofthe schematics of FIG. 5;

FIG. 7 is a schematic illustrating the method of extracting horizontaland vertical synchronization pulses from a TV receiver without makinginternal connections, when using a signal broadcast by a cooperative TVstation;

FIG. 8 is a sketch illustrating apparatus for modulating a received TVsignal by a video and/or chroma signal generated by the control unit ofFIG. 1;

FIG. 9 is a sketch illustrating the TV screen of a receiver employed ina coded information mode; and

FIG. 10 is a schematic of a decoder used to decode the informationpresent on the TV screen of FIG. 9.

DESCRIPTION OF PREFERRED EMBODIMENTS

The principal components of one embodiment of a television gaming systemconfigured according to the invention are illustrated in FIG. 1 which isa pictorial view showing a television receiver 10, a control unit 14 andmeans 12 for connecting control unit 14 to receiver 10. The televisionreceiver 10 employed can be any of the standard commercially availablemodels that are generally used for home entertainment. Either amonochrome or color television set may be used with the presentinvention since the basic principles of the invention apply to bothtypes. The connection means 12 is in this embodiment a shielded cable,for example, shielded twin lead and is attached to the antenna terminalsof receiver 10 in conventional fashion (see FIG. 1A). .Iadd.Thisconnection is a non-destructive connection (screw connection in theinstant example) which readily allows a user to switch from using thetelevision receiver for playing games to watching broadcast programs andvice versa without requiring the destruction of a permanent connectionsuch as a soldered connection. .Iaddend.

Control unit 14 generates video signals shown as "dots" 20₁ and 20₂which are positioned on the receiver screen 18 by knobs 16, 17, and 16₁,17₁, respectively. In this embodiment the "dots" 20 are squares orrectangles. However, any geometric shape is applicable. Knob 16 controlsthe vertical position of dot 20₁ while knob 17 controls the horizontalposition thereof. Thus, it can be seen that the dot 20₁, may bepositioned at any point on the screen by the proper manipulation ofknobs 16 and 17. Dot 20, is positioned in like manner by knob 16₁, 17₁.A reset switch 26 is shown on the control unit 14 and is used to resetthe picture on the television screen. For example, a game may be playedin which one dot is to be positioned over the other and when this isaccomplished one dot will disappear when a monochrome set is used, whilein a color set, the dot will disappear and the background will changecolor. When games of this nature are played, a reset means is requiredbefore play can be resumed. Reset switch 26 performs this function.

A knob 15 controls background color for color TV receiver applications.Alternatively, control unit 14 may be broken up into a master controlunit containing the electronic circuits and individual control unitscontaining control knobs 16, 17 and 16₁, 17₁, whereby each participantmay operate from a position not proximate the other and so not tointerfere with other players. This is illustrated in FIG. 1B whereincontrol unit 14 is broken up into a master control unit 21 andindividual control units 22 and 23. The master control unit 21 containsthe electronic circuitry found in control unit 14 and controls 26 and15. Knobs 16, 17 and 16₁, 17₁ which position the dots 20₁ and 20₂ aresituated on individual control units 22 and 23 respectively.

The knobs 16, 17 may be combined into a single joystick permittingcontrol of the horizontal and vertical dot positioning by a singlecontrol means.

Rather than provide a separate control unit, the control unit could bebuilt into the television receiver as a constituent part thereof and thereceiver sold as both an active and passive home entertainment system.

A typical sequence of steps to play a game using the present inventionwould be as follows: 1. Attach connection means 12 to TV set 10 atantenna terminals 19 if not already attached; 2. turn TV set on; 3.select the proper channel on the set for the control unit being used; 4.apply power to the control unit; 5. attach a mask on the face of the TVscreen, if required for the game to be played; 6. begin the game.

Referring now to FIG. 2, a television screen 18 is illustrated havingtwo "dots" 20₁ and 20₂ displayed. An overlay mask 30 of some type oftransparent material such as plastic or the like, having some type ofpattern, picture or other illustration pertaining to the particular gameto be played is shown in a lifted position. Prior to engaging in a game,the overlay mask 30 would be temporarily attached to television screen18 and in such close proximity to it as not to create any distortionwhen viewed with reference to the dots 20. One type of overlay maskcould be a checkerboard pattern to be used for playing a modified gameof checkers. Still another pattern could be a maze type, with the objectof the game being to escape within a specified time. These are but a fewof the many games that can be adapted for use with the presentinvention.

Alternatively, rather than employ overlay mask 30, the pattern to beprovided could be displayed directly on the screen 18. The pattern couldbe broadcast by TV stations or alternatively could be sent to a non-usedchannel over closed-circuit or CATV lines. This embodiment is describedin greater detail hereinafter with respect to FIGS. 7 and 8.

The control unit 14 will now be described in detail by referring to theblock diagram shown in FIG. 3. The timing for the television gamingsystem is established within the control unit by a horizontal syncgenerator 31 and a vertical sync generator 32.

The horizontal sync generator 31 employed in this embodiment is amultivibrator whose output is a series of pulses rather than a squarewave. The repetition rate of these pulses is the standard horizontalscanning frequency used in commercial television receivers. The positivesync pulse output 81 of the horizontal sync generator 31 issimultaneously applied to a first "dot" generator 34, a second "dot"generator 35 and a chroma generator 33 (in color TV applications). Thenegative sync pulse output 82 of the horizontal sync generator 31 isapplied directly to a summing amplifier-modulator 37. The "dot"generators 34 and 35 when triggered by horizontal sync generator 31generate a pulse which is the horizontal video information portion ofthe television composite signal that forms the "dots" 20 on thetelevision receiver screen 18. The manual control knobs 16, 17 and 16₁,17₁ on the control unit are attached to the shafts of potentiometers 86,92 and 95, 99 in the dot generator circuits of the "dot" generators 34and 35 respectively (see FIGS. 5C and 5D). Alternatively, a singlecontrol such as a joystick could be coupled to knobs 16, 17 and a secondjoystick coupled to knobs 16₁, 17₁. Adjustment of these potentiometersestablishes the position of the "dots" on the television screen.

The vertical sync generator 32 is coupled to the first and second symbolor "dot" generators 34 and 35 and triggers the "dot" generators togenerate a pulse which is the vertical video information portion of thecomposite television signal. The combination of the horizontal andvertical signals form a "dot" on the television receiver screen. Thereare two manual control knobs for each "dot". One of the knobs controlsthe horizontal pulse position while the other controls the verticalpulse position. The output of the "dot" generator which is the delayedhorizontal pulses that are gated by the delayed vertical pulse,describes the location of the "dots" on the television screen. Thehorizontal and vertical video information from the first and second"dot" generators 34 and 35 is summed together in the summing network ofsumming amplifier-modulator 37. The summing network is a resistor matrixwhich sums all the signals presented to one point. Thus the compositevideo information is formed. The composite video information is thencoupled to the modulator portion of summing amplifier-modulator 37 andto r-f oscillator 38 which modulates the video information with thecarrier to generate the modulated RF signal. The RF signal is thencoupled to the television antenna terminals 19. The RF signal that ispresent at the antenna terminals is detected and processed by thetelevision receiver in the standard manner and is displayed upon thescreen. The two controllable "dots" are the means by which games may beplayed.

Alternatively the video signal could be applied internally to thereceiver without rf carrier modulation.

The "dot" coincidence detector and crowbar circuit 40 receives an inputfrom both the first and second "dot" generators 34 and 35 taken atoutputs 94 and 98 thereof, respectively (see FIG. 5). When the "dots"20₁ and 20₂ are coincident, the first "dot" generator 34 is turned offby the "dot" coincidence detector and crowbar circuit 40. Thus, when one"dot" is superimposed upon the other, one of the "dots" will disappear.

A variety of games may be adapted to use this particular aspect of thetelevision gaming system. For example, a game of fox and hounds may beplayed with one "dot" representing the fox and other the hounds. Whenthe hounds catch the fox, the fox's "dot" disappears indicating a catch.Any game requiring an indication of when contact is made between twoobjects may be adapted to this concept.

The chroma generator 33 is used when the control unit 14 is coupled to acolor television receiver. Chroma generator 33 may be omitted formonochrome applications. The gaming system for color operation is thesame as that for monochrome sets with the exception that the backgroundcolor in the color receivers may be controlled. A color control knob 15(see FIG. 1) is provided on control unit 14 and is coupled to apotentiometer within the chroma generator 33 by which means thebackground color may be varied throughout its entire color spectrum. Thehorizontal sync generator 31 provides the trigger signal to the chromagenerator 33 whose output is then summed in the summing network of thesumming amplifier-modulator 37 with the other portions of videoinformation. The resultant composite video information is then modulatedwith the carrier in the modulator and r-f oscillator 38. The RF signalis then coupled as before to the television receiver antenna terminals19 and is detected, processed and displayed in the standard manner..Iadd.It should be noted that neither the synchronization system nor thechroma system conform to NTSC standards but is much simplified..Iaddend.

One game which may be played employing the concepts of this invention istarget shooting. A "toy" gun containing a photocell is electricallycoupled to the control unit.

When a game is played using the target gun, also called a "light-gun,"hits are shown on the screen by having one of the "dots" disappear.Signals detected by a target gun circuit 36 are used to trigger thecrowbar circuit portion of "dot" coincidence detector and crowbarcircuit 40, which turns off the first dot generator 34. Thus, one of thedots will disappear indicating a hit. The operation of the target guncircuits will be described in greater detail with reference to FIG. 4.

The power source 41 is preferably a .[.battern.]. .Iadd.battery.Iaddend.and provides the necessary power to operate the variouscircuits.

Referring now to FIG. 5, there is illustrated thereby schematics of theblocks of FIG. 3. The schematics are described in conjunction with thewaveforms of FIG. 6. Note that the circled capital letters A, B . . .designate connection points, that is A is coupled to A, B to B, etc. Thehorizontal oscillator 31 of FIG. 5A is an astable multivibrator thatoperates at approximately 15.75 KHz and generates the horizontal syncand timing pulses that are used within the control unit and thetelevision receiver. One output signal taken at point 81 is a positivesync pulse which in one embodiment is approximately 8 volts in amplitudeand has a pulse width of 4 microseconds. A second output signal taken atpoint 82 is a negative sync pulse which also is approximately 8 volts inamplitude and has a pulse width of 4 microseconds.

The vertical oscillator 32 of FIG. 5B is an astable multivibrator thatoperates at 60 Hz and provides positive 89 and negative 90 vertical syncpulses of approximately 8 volts amplitude and 1 millisecond duration.

The first "dot" generator 34 is illustrated in FIG. 5C and is comprisedof an "and" gate, and horizontal and vertical delay and pulse-formingcircuits. The delayed horizontal and vertical pulses (positive syncpulses) are AND-gated together to form the video information whichproduces one "dot" on the television screen. Both delay andpulse-forming circuits utilize the positive sync pulse transistor oftheir respective oscillators as its input transistor. The positive syncpulse from point 81 of the horizontal oscillator is used to trigger thehorizontal delay and pulse-forming circuits portion of the first dotgenerator. When the positive sync pulse, taken at point 81, is appliedat point 84, the pulse that appears at the output of the delay andpulse-forming circuit point 85 is delayed by the time constantestablished by the setting of potentiometer 86 and capacitor 87. Thedelay and pulse-forming circuit output passes through a pulse shaperhaving an R-C time constant of very short duration relative to thehorizontal oscillator frequency. The output of the pulse shaper is takenat a point 150. The time delay may be varied from 9 microseconds to 57microseconds which is substantially the entire range of the horizontalsweep period. The pulses which are generated by the horizontaloscillator, the horizontal delay and pulse-forming circuit and the pulseshaper, are shown in FIG. 6A as waveforms 60, 61, 62 and 63. Waveform 60represents the negative horizontal sync pulses taken at point 82;waveform 61 represents the positive horizontal sync pulses taken atpoint 81; waveform 62 represents the output from the delay andpulse-forming circuit taken at point 85 and waveform 63 represents theoutput from the pulse shaper taken at point 150.

The positive sync pulse taken at point 89 of vertical oscillator 32 isused to trigger the vertical delay and pulse-forming circuit portion ofthe first dot generator. The output signal appears at point 91 after atime delay which is determined by the setting of potentiometer 92 andcapacitor 93. The delay and pulse-forming circuit output passes througha pulse shaper having an R-C time constant of very short durationrelative to the vertical oscillator frequency. The output of the pulseshaper is taken at point 151. The time delay may be varied from 1.5milliseconds to 15.5 milliseconds which is substantially the entirerange of the vertical sweep period. The pulses which are generated bythe vertical oscillator, the vertical delay and pulse-forming circuit,and the pulse shaper are shown in FIG. 6B as waveforms 64, 65, 66, and67. Waveform 64 represents the negative vertical sync pulses taken atpoint 90; waveform 65 represents the positive vertical sync pulses takenat point 89; waveform 66 represents the output from the delay andpulse-forming circuit taken at point 91; and waveform 67 represents theoutput from the pulse shaper taken at point 151.

The video information that will be displayed on the television screen 18as a "dot" 20 is the summation of the outputs of the horizontal andvertical delay and pulse-forming circuit. When the delayed verticalpulse is at point 151, the delayed horizontal pulses at point 150 willbe gated through to the first "dot" generator output 94. The waveformsof FIG. 6C illustrate the signals 63 and 67 taken at points 150 and 151respectively in expanded form and the output signal from the first "dot"generator 68 taken at point 94. The signal 68 which is present at thefirst "dot" generator output 94 contains the horizontal and verticaldata that will be processed by the television receiver and displayed asa "dot" 20₁ on the screen.

The settings of potentiometers 86 and 92 control the horizontal andvertical position of the "dot" 20₁ on screen 18.

The second "dot" generator 35 (see FIG. 5D) is configured exactly as thefirst "dot" generator and operates in the same manner to provide videoinformation for the second "dot" 20₂. The input to the horizontal delayand pulse-forming circuit portion of the second "dot" generator isprovided at a point 96. The input to the vertical delay andpulse-forming circuit portion of the "dot" generator is provided at apoint 97. The output of the second "dot" generator is taken at a point98.

The "dot" coincidence and crowbar circuit 40 illustrated in FIG. 5E isconnected to the outputs of the first and second "dot" generators. Thecathode end of a diode 101 is connected to the output 94 of the first"dot" generator while the cathode end of a diode 102 is connected to theoutput 98 of the second "dot" generator. When the outputs of both "dot"generators coincide, a positive signal will be applied to the gate 103of a silicon controlled rectifier (SCR) 104. The cathode of SCR 104 istied to ground, while the anode thereof is connected at a point 106 topoint 105 in the first "dot" generator. The SCR 104 will turn on andclamp point 105 of the first "dot" generator to ground. Thus, the outputof the first "dot" generator will become zero as long as SCR 104 isconducting, causing the first "dot" on the television screen todisappear. After the "dots" are made non-coincident, the SCR 104 may bereset by momentarily depressing reset switch 26, which removes theground from point 105 of the first "dot" generator, allowing the first"dot" to reappear on the television screen.

The modulator and r-f oscillator illustrated schematically in FIG. 5F iscoupled by a resistive network comprising resistive element 108-111 (seeFIGS. 5A-5D) to the negative sync pulses of the horizontal and verticaloscillators and the output signals of the first and second "dot"generators. The r-f oscillator which operates at the selected televisionchannel carrier frequency is collector-modulated by the output of thesumming amplifier taken at point 112. The composite video signal whichis inductively coupled to pickup coil 113 is coupled to the televisionreceiver antenna terminals 19. The composite video signal is shown inFIG. 6D.

The chroma generator 33 illustrated in FIG. 5G is used only when thecontrol unit 14 is coupled to a color television receiver and iscomprised of a crystal-controlled oscillator, a variable phase shifterand an OR gate. The output of the crystal-controlled oscillator whichoperates at 3.579545 MHz is taken at point 115. The phase shifter isvariable over the approximate range of 0°-180° by a potentiometer 116.The reference phase signal (0°) 70 is coupled to point 117. The variablephase signal 71 is coupled to point 118. These signals are shown in FIG.6E and are displaced with respect to one another by the amount set inthe phase shifter by potentiometer 116. The output signal of the chromagenerator developed at point 119 is comprised of a chroma sync burst andthe chroma signal. The composite chroma signal 72 which is the output ofthe chroma generator is shown in FIG. 6F. The chroma sync burst is the0° phase reference signal. The chroma signal is the variable phasesignal whose phase is compared by the television receiver against thechroma sync burst. The phase difference between the two signalsdetermines the color to be displayed on the screen. The positive syncpulse from point 81 of the horizontal oscillator is used to gate 0°phase reference signal to point 119. The trailing edge of the positivegoing pulse at point 120 gates approximately 3-5 microseconds of the 0°phase referenced to point 119 to become the chroma sync burst. Thecomposite color information is summed to the modulator input 114 bycapacitor 121. The total composite video signal including the colorinformation is then modulated, as explained before for the monochromesignal, with the carrier and coupled to the television antenna terminals19.

Alternately the video and/or chroma signals may be applied to thecrowbar modulator 126 of FIG. 8. (This will be described hereinafter).

When the gaming system is being used in either the target gun or "dot"coincident mode with a color TV receiver, the background color willchange when the "dot" disappears from the television screen. The anodeof SCR 104 of the coincidence detector and crowbar circuit 40 which isconnected to point 105 of the first "dot" generator to make the "dot"disappear is also connected to point 122 of the chroma generator. Whenthe chroma generator is adjusted for a red background, the backgroundwill change to blue when point 122 is clamped to ground by SCR 104. TheSCR 104 will be fired either by coincidence of the "dots" or byalignment of the photo cell in the target gun with the target "dot".

Turning now to FIG. 4, the target gun circuits 36 are shownschematically. When the target gun is pointed at the target "dot" on thetelevision screen, a photocell 50 mounted at the end of the target gunbarrel will detect the intensity modulated "dot." The detected signal isamplified by transistors 51 and 52. When the gun trigger switch 53 isclosed, the amplified detected signal is applied to the gate electrodeof a silicon controlled rectifier (SCR) 104, which will file SCR 104.The SCR 104 now clamps the output of the "dot" generator 34 to groundand the "dot" 20₁ will disappear. Whether the first or the second "dot "is used as a target does not matter, since a hit will be indicated bythe disappearance of the first "dot". If only one "dot" is to bedisplayed on the screen as a target, the first "dot" would be used. Areset button 26 is provided to make the target reappear after a hit hasbeen scored. The portion of the circuit appearing within the dashedlines 56 is part of the "dot" coincidence and crowbar circuit 40.

An adjustment is provided by means of potentiometer 57 whereby thethreshold level of photo cell 50 may be adjusted such that only when thegun is properly aligned with the target will the "dot" disappear. Thisprocedure assures that false hits due to stray or scattered light fromthe room will not be scored. The setting should be made so that SCR 104will now be triggered by the brightness of the room but only theintensity of the displayed "dot."

As previously mentioned, this invention may be employed in conjunctionwith information originating from a cooperative station such as acommercial TV, a closed-circuit TV or a CATV station. In theseembodiments means are necessary for extracting the horizontal andvertical synchronization pulses from the TV receiver which is receivinga signal from a cooperative station. The horizontal and verticalsynchronization pulses could be obtained from within the TV receiverdirectly. However, this necessitates making electrical connections tothe internal circuitry of the TV receiver. Preferably, the apparatusillustrated in FIG. 7 is used to derive the synchronization pulses.

A device 129 is positioned in front of the receiver and attached to itby, for example, a suction cup at approximately the center bottom edgeof the CRT glass face (see FIG. 1D). Device 129 contains both aphotocell 128 and a pickup coil 123 responding broadly to 15,570 Hz.These devices pick up a 60 cycle signal component provided by a whitestripe at the bottom of the CRT, (generated by the cooperative station)and a radiated 15,570 horizontal scan signal, respectively. Thesesignals are applied via a cable 130 to a pair of amplifiers 127(vertical) and 124 (horizontal) and fed to a pair of pulse shapers 125(vertical) and 125₁ (horizontal). This yields synchronization pulseswhich duplicate in rate and phase those transmitted. Applying thesepulses to points 82 and 90 in FIGS. 5A and 5B allows locking thehorizontal and vertical oscillators into sync with the transmittedsignals. Consequently, all of the functions previously described, suchas the generation of "dots" for checker type games, target shooting,chase games and all other functions available to control by the"viewer," may now be overlaid the transmitted TV picture. Modulation inthis mode of operation is accomplished by the "crowbar" modulationcircuit 126 of FIG. 8.

In this Figure, use is made of an attenuator consisting of two seriesresistors 132 and 133 and a transistor 134 acting as a variable shuntresistor. Biasing this transistor sufficiently into conduction byapplying modulation to its base, saturates the transistor, momentarilyreducing the RF signal going from the antenna to the TV receiver antennaterminals 19. This corresponds to carrier reduction, which is negativemodulation and is equivalent to generating a video signal going fromblack to white and back to the black level. Chroma signals can also beapplied to the crowbar transistor modulator in the same fashion.

Note that the combination of apparatus described in FIGS. 7 and 8describe a mode of interacting with a transmitted TV signal withoutrequiring the attachment of connections to the internal circuitry of theTV receiver.

As mentioned above, the invention may be employed in conjunction with acooperative TV station such as commercial TV, closed-circuit TV and CATV(community antenna television). In this mode the invention may beemployed for target shooting or for decoding messages on a TV screen,such messages being the result of transmission from the cooperativestation, as for example testing with coded answer supplied. Othertransmissions can be transmissions from organizations offering servicesto the .[.equipped viewer where the services offered may be typicallyConsumer Products Buying Recommendations, Stock "Buy-Sell-Hold"recommendations and others involving the presentation of valuableinformation available to the.]. viewer equipped in accordance with thisinvention.

In FIG. 10 there is illustrated a combination target shooting anddecoding apparatus. The decoding portion thereof is described inconnection with the sketch of FIG. 9. Although the circuit shown is usedfor both decoding and target shooting it will be obvious that certain ofthe components can be eliminated to provide either of the functionsalone.

The information is presented on the TV screen in such a manner that aportion thereof is coded. For example, FIG. 9 illustrates using thepresentation for testing. The question and a group of possible answersis presented on TV screen 18 as illustrated with symbols 152-155 shownnext to each answer. One of the symbols (in the example shown 153) iscoded in such a manner that it will trigger the decoder of FIG. 10. Forexample, symbols 152, 154 and 155 may flash 60 times whereas the correctanswer symbol 153, will flash 61 times. The decoder of FIG. 10 isarranged to respond to the odd number of flashes.

The electronics of FIG. 10 can be inserted into a "gun" or othersuitable configuration and therefore be easily handled.

Referring now to FIG. 10, initially pressing a reset switch 142 sets theequipment. Reset switch 142 is a double pole single throw switch. Themodulation from the coded symbol incident at a photocell 136 is suppliedvia a buffer amplifier 137, and an amplifier and pulse shaper 138 to aflip-flop 139 which is triggered. The output from flip 139 is appliedvia a buffer amplifier 141 to a lamp 140 which will light with a steadyglow until reset indicating the correct answer was chosen.

If an incorrect answer was chosen, the lamp will flicker for a timeequal to the time the symbol (152, 154, 155) is being modulated and thenwill go out.

To go to the next question, the decoder is returned to its startingposition by operating reset switch 142. Note: initially reset switch hadto be depressed so that the flip-flop would be in the proper state toprovide a steady output to the lamp when photocell 139 receives an oddnumber of cycles.

To operate the circuit of FIG. 10 in its target shooting mode, a switch145 is switched to the alternate contacts 146, 147.

In this mode, (see FIG. 1C) a "target" dot 148 is supplied by thecooperative station which also could supply background scenery foraesthetic purposes. When the "gun" 27 (FIG. 1C) is aimed at the target148 and the trigger (switch 144 FIG. 10) is depressed, photocell 136will supply an output via buffer amplifier 137 and buffer amplifier andpulse shaper 138 to the gate electrode of a silicon controlled rectifier149 which causes SCR 149 to fire and light lamp 140. Switch 142 alsoresets SCR 149 turning off lamp 140.

FIG. 1E illustrates an alternate embodiment to that described above. Theoutput from the target shooter is applied to a crowbar circuit 24 theoutput of which is applied to antenna terminals 19 such that the screen18 will also flash white when a "hit" is made.

The principles hereinabove set forth apply with equal strength to bothmonochrome and color applications. While the system that has beendescribed has been basically for monochrome television sets, theprovisions for color operation have been described and may be applied togames utilizing the aspects of the ability to adjust or change thebackground color. Thus, it can be seen that a game such as roulette maybe played having for its object the guessing of the color that willappear when the wheel stops spinning. Very readily the system can beused to indicate a hit in the target game both by the disappearance ofthe square and by the change in background color. These are but a few ofthe countless variations that may be applied to this concept.

The number and variations of games which may be played are limited onlyby the imagination of the players. Some of the games which may be playedare overlay games, target shooting games, chase games and color games.

FIG. 2 illustrates one type of overlay games, namely a modifiedcheckerboard game. One player tries to move his "dot" 20₁ from A to Bwhile the other player tries to move his "dot" 20₂ from B to A. The"dots" may be moved orthonogally only and only one square at a time. Itis one object of this game to avoid checkmate. Other overlay games willbe readily apparent.

Another type game is a chase game. For example, a fox hunt can besimulated. This requires 3 players, a hunter, a fox and a score keeper.The hunter tries to catch the fox (indicated by the fox's "dot"disappearing within a specified time. Numerous variations on this gameare also possible with and without overlay patterns.

If the receiver employed is a color receiver then color games may beplayed. For example, an inertia wheel may be put on the shaft ofpotentiometer 116 in the chroma generator. The object of the game is fora player to guess the color which will appear when the wheel is spun.

The target shooting game is yet another game which is applicable to thisinvention. One player may manually move a "dot" while another tries to"hit" the "dot" with the photocell gun. Alternatively, the target may beautomatically moved by, for example, driving the biasing voltage for thedelay and pulse-forming circuit in a "dot" generator with a variablevoltage source.

It .[.should also be understood that the principles are not to belimited only to the gaming aspects but may be applied in the areas ofscientific, educational, clinical and other applications. Hence, it.].is to be understood that the embodiments shown are to be regarded asillustrative only, and that many variations and modifications may bemade without departing from the principles of the invention hereindisclosed and defined by the appended claims.

I claim: .[.
 1. In combination with a standard television receiver,apparatus for generating "dots" upon the screen of the receiver to bemanipulated by a participant, comprising:a control unit for generatingsignals representing the "dots" to be displayed, said control unitfurther including means for generating synchronizing signal tosynchronize the television raster scan of said receiver and means formanipulating the position of the "dots" on the screen of said receiver;and means for directly coupling the generated signals only to saidtelevision receiver whereby said "dots" are displayed only upon thescreen of said receiver being viewed by the participant..]. .[.
 2. Thecombination of claim 1 wherein said control unit includes:a horizontalsync generator; a vertical sync generator; at least one dot generatorcoupled to said horizontal and vertical sync generators; means forgenerating an rf signal; and means for modulating said rf signal with anoutput signal from said dot generator, said modulated rf signal beingcoupled to said television receiver..]. .[.3. The combination of claim 2wherein said horizontal sync generator includes an astable multivibratorand said vertical sync generator includes as astable multivibrator..]..[.4. The combination of claim 2 wherein said "dot" generator includeshorizontal and vertical delays and an AND gate coupling the outputs fromsaid delays..]. .[.5. The combination of claim 2 wherein said means forgenerating a modulated rf signal includes:means for summing the signaloutputs from said horizontal sync generator, said vertical syncgenerator and said dot generator to provide a video signal; and meansfor modulating the video signal with a carrier signal the frequency ofwhich is selected in accordance with which channel of the televisionreceiver the "dots" are to be displayed..]. .[.6. The combination ofclaim 2 wherein said dot generator includes means for varying theposition of the generated "dots" on the television receiver screen..]..[.7. The combination of claim 2 wherein said control unit includesfirst and second dot generators coupled to said vertical sync generatorand said horizontal sync generator..]. .[.8. The combination of claim 7wherein said means for generating a modulated rf signal includes: meansfor summing the signal outputs from said horizontal sync generator, saidvertical sync generator and said first and second dot generators toprovide a video signal; and means for modulating the video signal with acarrier signal the frequency of which is selected in accordance withwhich channel of the television receivers the "dot" are to bedisplayed..]. .[.9. The combination of claim 8 wherein each of said dotgenerators includes means for varying the position of the generated"dots" on the television receiver screen..]. .[.10. The combination ofclaim 9 wherein said position varying means includes a control forvarying the vertical position of each generated "dot" and a control forvarying the horizontal position of each generated "dot"..]. .[.11. Thecombination of claim 9 wherein said position varying means includes onecontrol for varying the horizontal and vertical position of eachgenerated "dot.".]. .[.12. The combination of claim 11, said controlbeing a joystick..]. .[.13. The combination of claim 9, furtherincluding means for denoting coincidence when a "dot" generated by oneof said dot generators is located in the same position on the televisionscreen as a "dot" generated by another of said dot generators..]. .[.14.The combination of claim 13 wherein said coincidence denoting meansincludes a coincidence detector and crowbar circuit coupled to saidfirst and second dot generators such that coincidence of position ofsaid "dots" will be indicated by having said first dot generator turnedoff causing disappearance on the screen of the television receiver ofits respective "dot.".].
 15. The combination of claim .[.14.]. .Iadd.50.Iaddend.wherein said coincidence detector and crowbar circuit includesa semiconductor switch and means for turning on said switch when asignal is received simultaneously from said first and second dotgenerators.
 16. The combination of claim .[.14.]. .Iadd.50.Iaddend.,further including means for resetting said coincidence denoting meansafter the "dots" are made noncoincident.
 17. The combination of claim.[.14.]. .Iadd.50.Iaddend., further including means operativelyresponsive to .Iadd.the presence of .Iaddend.a displayed "dot" .Iadd.ata location upon said screen of said receiver.Iaddend..
 18. Thecombination of claim 17, wherein said means responsive includes:meansfor sensing light; and means for actuating said coincidence denotingmeans when said light sensing means detects a "dot" displayed on thetelevision receiver screen.
 19. The combination of claim 18 wherein saidactuating means includes a switch which couples the output from saidlight sensing means to said coincidence denoting means.
 20. Thecombination of claim 19 wherein said light sensing means is aphotosensitive element arranged within the barrel of a toy gun. .[.21.The combination of claim 14 in which said television receiver is a colorreceiver, said combination further including a chroma generator havinginputs from said horizontal sync generator and said coincidence denotingmeans and an output to said signal summing means, such that coincidencewill also be indicated by a changing of background color of saidtelevision receiver screen..].
 22. The combination of claim .[.21.]..Iadd.48 .Iaddend.wherein said chroma generator includes a control forvarying the background color of the television receiver screen.
 23. Thecombination of claim 22 further including a wheel coupled to saidcontrol for varying background color which when spun will cause thebackground color to be of non-predetermined selection. .[.24. Thecombination of claim 1, further including an overlay mask attached tothe television receiver screen, said overlay mask having a predeterminedpattern thereon..]. .[.25. The combination of claim 1, further includingmeans for automatically moving said "dots" about said televisionscreen..].
 26. .[.The.]. .Iadd.In .Iaddend.combination .[.of claim 25,further including.]. .Iadd.with a raster scan home television receiverpreviously employed only for passive viewing of programs, apparatus foradding active home entertainment capability to the home televisionreceiver by generating "dots" upon the screen of the receiver to bemanipulated by a participant, comprising:a control unit for generatingsignals representing the "dots" to be displayed, said control unitfurther including means for generating synchronizing signals tosynchronize the television raster scan of said receiver, means formanipulating the position of at least one of the "dots" on the screen ofsaid receiver to play amusement games and means for permitting alternatemovement of said "dots" wherein said alternate movement means includesmeans for automatically moving at least one of said "dots" about saidtelevision screen; means for directly coupling the generated signalsonly to said television receiver, wherein the receiver is also adaptedto receive broadcast television signals, whereby said "dots" aredisplayed only upon the screen of said receiver being viewed by theparticipant; and .Iaddend. means for "shooting" at said moving "dots",said "shooting" means including light responsive means responsive.Iadd.only .Iaddend.to a displayed "dot" .Iadd.when aligned therewithand disposed a substantial distance from the television screen whenplaying a shooting game thereby simulating actual target shooting, saidlight responsive means not being responsive to the television rasterscan of said receiver except where the raster is modulated to display adot.Iaddend..
 27. .[.The.]. .Iadd.In .Iaddend.combination .[.of claim 1,further including.]. .Iadd.with a raster scan home television receiver,apparatus for permitting the playing of amusement games on the screen ofthe television receiver by generating "dots" upon the screen of thereceiver to be manipulated by a participant, comprising:a control unitfor generating signals representing the "dots" to be displayed, saidcontrol unit further including means for generating synchronizingsignals to synchronize the television raster scan of said receiver andmeans for manipulating the position of the "dots" on the screen of saidreceiver; means for directly coupling the generated signals only to saidtelevision receiver wherein the receiver is also adapted to receivebroadcast television signals, whereby said "dots" are displayed onlyupon the screen of said receiver being viewed by the participant; and.Iaddend.and means for "shooting" at said "dots," said "shooting" meansincluding light responsive means responsive .Iadd.only .Iaddend.to adisplayed "dot" when aligned therewith .Iadd.and disposed a substantialdistance from the television screen when playing a shooting game therebysimulating actual target shooting, said light responsive means not beingresponsive to the television raster scan of said receiver except wherethe raster is modulated to display a dot.Iaddend.. .[.28. Televisiongaming apparatus as defined in claim 27, further including means forcausing one of said "dots" to disappear when said "shooting" meansreceives light from a displayed "dot"..]. .[.29. Television gamingapparatus as defined in claim 27 in which said television receiver is acolor receiver, further including means for causing the background colorof said television screen to change color when a "hit" is made..]..[.30. The combination of claim 27 wherein said light responsive meansincludes a photocell..]. .[.31. The combination of claim 1, furtherincluding means for receiving background information generated on thetelevision receiver screen by a cooperative television station..]..[.32. In combination with a standard television receiver includinghorizontal and vertical deflection circuitry which is synchronized withhorizontal and vertical synchronization signals, apparatus forgenerating "dots" upon the screen of the receiver to be manipulated by aparticipant, comprising:a control unit responsive to the horizontal andvertical synchronization signals for generating signals representing"dots" to be displayed, including means for manipulating the position ofthe "dots" on the screen of the receiver; and means for directlycoupling the generated signals only to said television receiver wherebysaid "dots" are displayed only upon the screen of said receiver beingviewed by the participant..]. .[.33. The combination of claim 32,further including: means for receiving information generated by acooperative television station; and means for applying the receivedinformation to said television receiver to be displayed thereby..]..[.34. The combination of claim 33 wherein said applying means includesmeans for modulating said received information by said generatedsignals..]. .[.35. The combination of claim 34 wherein said modulatingmeans includes means for momentarily causing a reduction of signalstrength of said received information when generated signals are beingapplied, whereby the generated "dots" are displayed at their particularposition of the screen in place of the received information..]. .[.36.The combination of claim 33, further including means synchronizing thegenerated signals with the received information..]. .[.37. Thecombination of claim 36 wherein said synchronizing means includes:meansfor receiving a horizontal scan signal generated by the televisionstation; and means for detecting a vertical synchronizing componentprovided on the screen of the television receiver..]. .[.38. Thecombination of claim 37 wherein said means for receiving a horizontalscan signal includes a pickup coil and said means for detecting avertical synchronizing component includes a photocell..]. .[.39. Thecombination of claim 36 wherein said synchronizing means is mechanicallycoupled to the television screen..]. .[.40. Apparatus for generating"dots" upon the screen of a television receiver to be manipulated by aparticipant, comprising:a control unit for generating signalsrepresenting the "dots" to be displayed, said control unit furtherincluding means for generating synchronizing signals to synchronize atelevision raster scan of a receiver and means for manipulating theposition of the "dots" on the screen; and means for directly couplingthe generated signals only to a single television receiver whereby said"dots" are displayed only upon the screen of the single receiver beingviewed by the participant.]..
 41. Apparatus .[.as in claim 40, furtherincluding.]. .Iadd.for permitting the playing of amusement games on thescreen of a raster scan home television receiver by generating "dots"upon the screen of the raster scan television receiver to be manipulatedby a participant, comprising:a control unit for generating signalsrepresenting the "dots" to be displayed, said control unit furtherincluding means for generating synchronizing signals to synchronize atelevision raster scan of a receiver and means for manipulating theposition of the "dots" on the screen; means for directly coupling thegenerated signals only to a single television receiver, wherein thereceiver is also adapted to receive broadcast television signals,whereby said "dots" are displayed only upon the screen of the singlereceiver being viewed by the participant; and .Iaddend. means for"shooting" at said "dots", said means including light responsive meansresponsive .Iadd.only .Iaddend.to a displayed "dot.[...]." .Iadd.whenaligned therewith and disposed a substantial distance from thetelevision screen when playing a shooting game thereby simulating actualtarget shooting, said light responsive means not being responsive to thetelevision raster scan of said receiver except where the raster ismodulated to display a dot. .Iaddend.
 42. .[.The.]. .Iadd.In.Iaddend.combination .[.of claim 1 wherein said control unit includes.]..Iadd.with a standard raster scan home television receiver, apparatusfor generating "dots"upon the screen of the receiver to be manipulatedby a participant, comprising:a control unit for generating signalsrepresenting the "dots" to be displayed wherein said control unitincludes means for generating synchronizing signals to synchronize thetelevision raster scan of said receiver comprising .Iaddend. means forproviding horizontal sync signals.[.;.]. .Iadd.and .Iaddend. means forproviding vertical sync signals; a first RC network coupled to saidmeans for providing horizontal sync signals; a second RC network coupledto said means for providing vertical sync signals; a first transistorcoupled to said first RC network; a second transistor coupled to saidsecond RC network; first pulse shaping means coupled to the output ofsaid first transistor; second pulse shaping means coupled to the outputof said second transistor; .[.and.]. an AND gate coupled to said firstand second pulse shaping means.Iadd.; means for manipulating theposition of the "dots" on the screen of said receiver; and means fordirectly coupling the generated signals only to said television receiverwhereby said "dots" are displayed only upon the screen of said receiverbeing viewed by the participant.Iaddend.. .[.43. The combination ofclaim 1 wherein at least two "dots" are displayed on the screen of saidreceiver..]. .[.44. Apparatus for use within a television receiver,which receiver includes horizontal and vertical deflection circuitrywhich is synchronized with horizontal and vertical synchronizingsignals, said apparatus including means for generating "dots" upon thescreen of said receiver to be manipulated by a participant, comprising:acontrol unit responsive to the horizontal and vertical synchronizingsignals for generating signals representing "dots" to be displayed,including means for manipulating the position of the "dots" on thescreen of said receiver whereby said "dots" are displayed only upon thescreen of said receiver..]. .[.45. Apparatus as in claim 44 wherein saidhorizontal and vertical synchronization signals are received from atelevision station..]. .[.46. Apparatus as in claim 45 wherein saidreceived synchronization signals are the standard synchronizationsignals generated by the television station..]. .Iadd.47. Apparatus foradding active home entertainment capability to a home raster scantelevision receiver previously employed only for the passive viewing ofprograms by permitting the playing of games on the screen of thetelevision receiver by at least one participant and generating "dots"upon the screen of the television receiver to be manipulated by aparticipant, said apparatus comprising: .Iadd.a control for generatingsignals representing the "dots to be displayed, said control unitfurther including means for generating horizontal and verticalsynchronizing signals to synchronize a television raster scan of areceiver, means for generating first signals representing the horizontalposition of said "dots", means for generating second signalsrepresenting the vertical position of said "dots", means formanipulating the position of the "dots" on the screen for playingamusement games, and AND gate circuitry for AND gating selected ones ofsaid first and second signals representing two of said dots fordetecting coincidence of said two dots; andmeans for directly andselectively coupling the generated signals representing the dots to bedisplayed and the synchronizing signals only to a single televisionreceiver whereby in a first state said "dots" are displayed only uponthe screen of the single receiver being viewed by the participant and ina second state such television receiver is capable of receivingbroadcast television signals. .Iaddend. .Iadd.48. In combination with astandard raster scan home color television receiver, apparatus forgenerating "dots" upon the screen of the receiver to be manipulated by aparticipant, comprising:a control unit for generating signalsrepresenting the "dots" to be displayed, said control unit furtherincluding means comprising a horizontal sync generator and a verticalsync generator for generating synchronizing signals to synchronize thetelevision raster scan of said receiver, first and second dot generatorscoupled to said vertical sync generator and said horizontal syncgenerator and each including means for manipulating and varying theposition of the generated "dots" on the television receiver screen,means for denoting coincidence when a "dot" generated by one of said dotgenerators is located in the same position on the television screen as a"dot" generated by another of said dot generators, and a chromagenerator having inputs from said horizontal sync generator and saidcoincidence denoting means, said coincidence denoting means including acoincidence detector and crowbar circuit coupled to said first andsecond dot generators such that coincidence of position of said "dots"will be indicated by having said first dot generator turned off causingdisappearance on the screen of the television receiver of its respective"dot" and such that coincidence will also be indicated by a changing ofbackground of color of said television receiver screen; means forgenerating an rf carrier signal of desired frequency; and means formodulating said rf carrier signal with an output signal from said dotgenerators including means for summing the signal outputs from saidhorizontal sync generator, said vertical sync generator, said chromagenerator and said first and second dot generators to provide a videosignal, and means for modulating the video signal onto said carriersignal the frequency of which is selected in accordance with whichchannel of the television receiver the "dots" are to be displayed, saidmodulated rf signal being coupled to said television receiver; and meansfor directly coupling the generated signals only to said televisionreceiver whereby said "dots" are displayed only upon the screen of saidreceiver being viewed by the participant. .Iaddend. .Iadd.49. Incombination with a standard raster scan home color television receiver,apparatus for generating "dots" upon the screen of the receiver to bemanipulated by a participant, comprising: a control unit for generatingsignals representing the "dots" to be displayed, said control unitfurther including means for generating synchronizing signals tosynchronize the television raster scan of said receiver and means formanipulating the position of the "dots" on the screen of said receiver;means for directly coupling the generated signals only to saidtelevision receiver, wherein the receiver is also adapted to receivebroadcast television signals, whereby said "dots" are displayed onlyupon the screen of said receiver being viewed by the participant; meansfor "shooting" at said "dots," said "shooting" means including lightresponsive means responsive only to a displayed "dot" when alignedtherewith and disposed a substantial distance from the television screenwhen playing a shooting game thereby simulating actual target shooting,and said light responsive means not being responsive to the televisionraster scan of said receiver except where the raster is modulated todisplay a dot; and means for causing the background color of saidtelevision screen to change color when a "hit" is made. .Iaddend..Iadd.50. In combination with a standard raster scan home televisionreceiver, apparatus for generating "dots" upon the screen of thereceiver to be manipulated by a participant, comprising: a control unitfor generating signals representing the "dots" to be displayed, saidcontrol unit further including means comprising a horizontal syncgenerator and a vertical sync generator for generating synchronizingsignals to synchronize the television raster scan of said receiver,first and second dot generators coupled to said vertical sync generatorand said horizontal sync generator and each including means formanipulating and varying the position of the generated "dots" on thetelevision receiver screen and means for denoting coincidence when a"dot" generated by one of said dot generators is located in the sameposition on the television screen as a "dot" generated by another ofsaid dot generators, said coincidence denoting means including acoincidence detector and crowbar circuit coupled to said first andsecond dot generators such that coincidence of position of said "dots"will be indicated by having said first dot generator turned off causingdisappearance from the screen of the television receiver or itsrespective "dot"; means for generating an rf carrier signal; and meansfor modulating said rf carrier signal with an output signal from saiddot generators including means for summing the signal outputs from saidhorizontal sync generator, said vertical sync generator and said firstand second dot generators to provide a video signal and means formodulating the video signal onto said rf carrier signal the frequency ofwhich is selected in accordance with which channel of the televisionreceiver the "dots" are to be displayed, said modulated rf signal beingcoupled to said television receiver; and means for directly coupling thegenerated signals only to said television receiver whereby said "dots"are displayed only upon the screen of said receiver being viewed by theparticipant..Iaddend. .Iadd.51. In combination with a standard rasterscan home television receiver including horizontal and verticaldeflection circuitry which is synchronized with horizontal and verticalsynchronization signals, apparatus for generating "dots" upon the screenof the receiver to be manipulated by a participant, comprising:a controlunit responsive to the horizontal and vertical synchronization signalsfor generating signals representing "dots" to be displayed, includingmeans for manipulating the position of the "dots" on the screen of thereceiver; means for directly coupling the generated signals only to saidtelevision receiver where said "dots" are displayed only upon the screenof said receiver being viewed by the participant; means for receivinginformation generated by a cooperative television station and forapplying the received information to said television receiver to bedisplayed thereof; and means synchronizing the generating signals withthe received information, said synchronizing means including means forreceiving a horizontal scan signal generated by a television stationincluding a pickup coil and means for detecting a verticalsynchronization component provided on the screen of a televisionreceiver including a photocell. .Iaddend. .Iadd.52. In combination witha raster scan home television receiver, apparatus for permitting theplaying of amusement games on the screen of the television receiver bygenerating "dots" upon the screen of the receiver to be manipulated by aparticipant, comprising:a control unit for generating signalsrepresenting the "dots" to be displayed, said control unit furtherincluding means for generating synchronizing signals to synchronize thetelevision raster scan of said receiver and means for manipulating theposition of the "dots" on the screen of said receiver; means fordirectly coupling the generated signals only to said televisionreceiver, wherein the receiver is also adapted to receive broadcasttelevision signals whereby said "dots" are displayed only upon thescreen of said receiver being viewed by the participant; means for"shooting at said "dots", said "shooting" means including lightresponsive means responsive only to a displayed "dot" when alignedtherewith and disposed a substantial distance from the television screenwhen playing a shooting game thereby simulating actual target shooting,said light responsive means not being responsive to the televisionraster scan of said receiver except where the raster is modulated todisplay a dot; and means for causing one of said "dots" to disappearwhen said "shooting " means receives light from a displayed "dot"..Iaddend.